Struts 2 - Interceptor reset the response JSON Object

问题

I am using Struts 2 in my web application. I write code to check user session into interceptor but while I am returning net.sf.json.JSONObject as response, its reset the response object and set null to the object. Please check my code.

import net.sf.json.JSONObject;
import com.opensymphony.xwork2.interceptor.Interceptor;

public class AuthorizationInterceptor implements Interceptor {

JSONObject response = new JSONObject();

public String intercept(ActionInvocation invocation) {
 try { 
      Map session = invocation.getInvocationContext().getSession();
        if (session.get("userId") == null) {
           response.put("errorCode", "SESSION_OUT");                
            return ActionSupport.ERROR;
        } else {
            System.out.println("Session found");
            Object action = invocation.getAction();
            return invocation.invoke();
        }
    } catch (Exception e) {
        return ActionSupport.ERROR;
    }
}

public JSONObject getResponse() {
    return response;
}

public void setResponse(JSONObject response) {
    this.response = response;
}

}

How can I get the JSON Object as response from interceptor. Please help me to resolve this issue.

回答1:

There are mutliple errors in your code.

Response is HttpServletResponse, you should not give that name to a JSONObject.
Interceptors are NOT THREAD-SAFE, that means that you should define the JSONObject inside the method, to prevent multiple users to update it concurrently, one over the other
You should use statusCode or errorCode as described in the JSON plugin documentation, by configuring it as the Error result you are returning:

Use statusCode to set the status of the response:

<result name="error" type="json">
  <param name="statusCode">304</param>
</result>

And errorCode to send an error(the server might end up sending something to the client which is not the serialized JSON):

 <result name="error" type="json">
  <param name="errorCode">404</param>
</result>

and then read it client-side in the AJAX callback function.

来源：https://stackoverflow.com/questions/17234976/struts-2-interceptor-reset-the-response-json-object

标签

java

json

struts2

interceptor